User:Richard.decal/Sia

Sia is a cooperative file storage network platform that leverages the Siacoin token, smart contracts, and blockchain technology to safely store data on hosts distributed throughout the world. It is written in the language Go and actively developed by Nebulous Inc.

History
Sia began in September 2013 as a project by David Vorick and Luke Champine when they were both undergraduate computer science students at Rensselaer Polytechnic Institute in Troy, New York. The original Sia project was conceived at HackMIT 2013.

While most cryptocurrency projects at the time focused on digital assets as a medium of exchange, Vorick and Champine theorized about a better system that would create intrinsic value for their holders by using their token as payment for file storage. Vorick created Siacoin "to provide infrastructure that nobody, including ourselves, has the control over [...] something with no failure points, where there is no place of leverage and no company, country, jurisdiction, person who can decide that they don't like you or they have ulterior motives."

Vorick and Champine created Nebulous Inc. in May 2014. Nebulous was initially funded by a September 2014 seed round of $750,000 from investors including Procyon Ventures, Raptor Group,  Fenbushi Capital,  and angel investor Xiaolai Li. Nebulous raised an additional estimated $500,000 from Siafunds (SF) sale in May 2014 and $400,000 via grant from INBlockchain in July 2017 for a total of $1.7 million.

The first public beta was released in March 2015 with version 1.0.0 being released in June 2016. The most recent release was version 1.3.1 in December 2017.

Concept
Sia is a decentralized file storage system that incentivizes people to rent out their unused hard disk drive space to earn Siacoin, or SC. It does this by using a blockchain technology whose design is similar to Bitcoin with a few unique technical tweaks that allow it to be used efficiently for file storage. The main difference is the "file contract", a special kind of blockchain smart contract that provides a way for hosts (people offering storage space for rent) to get paid for proving that they have stored a file and made it available for a user over a period of time. To protect user privacy, all data is encrypted before being uploaded to the network, and only the user can decrypt them again. Other technologies like payment channels further optimize the Sia network for file storage. Combining this with redundancy and error-correction, codes yields a self-bootstrapping ecosystem where the cheapest available excess storage capacity is automatically used preferentially by the network.

Sia's file contracts allow for monthly storage costs of about $2 per terabyte, compared to a cost of $4 for Amazon Glacier and $23 for Amazon S3.

Design Features
Sia is written in Go. It runs on 64-bit versions of Windows, Mac OS X and Linux.

Sia has both a graphical user interface for end users as well as a commandline version for use in headless environments. Both interfaces use the same core and have the same set of features and capabilities.

Sia splits up files into small pieces and stores the pieces across multiple hosts using Reed–Solomon encoding. This encoding enables Sia to achieve a 3x redundancy, ensuring that even if multiple hosts go offline, the renter will still have access to their files. Merkle trees allow the storage hosts to provide cryptographic zero-knowledge proof that it still stores the files. These proofs are tested continually by the storage network, with hosts failing to prove storage too many times losing their staked collateral. Hosts are expected to have 95 to 98 percent uptime, compared to 99.9% for conventional cloud storage providers.

Siacoin
Siacoin (SC) is the cryptocurrency used to buy and sell storage on the Sia platform. Siacoin uses a Proof-of-Work (PoW) consensus protocol incorporating BLAKE2b as its hash function.

Siacoin is created through proof-of-work mining with a target block time of 10 minutes to prevent Sybil attacks and to secure the network Sia plans to utilize a proof-of-burn algorithm to manage inflation and control the number of Siacoins in circulation. Annual inflation ex-burn is projected to fall below 4% in mid-2020 and below 3% in mid-2025 when block reward decreases from 300,000 in the genesis block to 30,000 on block 270,000. In mid-2025, the coin supply ex-burn is projected to be approximately 52 billion. Nebulous Inc. holds less than 1% of all Siacoin.

Between January and June 2017, the market capitalization of Siacoin increased almost 100-fold from $5.3 million to $527.8 million. In June 2017, Siacoin was the 16th largest cryptocurrency by market cap. In July 2017, Forbes named Siacoin in their top 25 crypto assets, describing it as "decentralized file storage that’s a tenth of the cost, faster and more reliable [than Amazon S3]". On January 7, 2018, Siacoin's market cap reached an all-time high of $3.08 billion.

Siafunds
Siafunds (SF) are a second cryptocurrency built into the Sia platform. 10,000 Siafunds exist; 1,175 Siafunds were sold in May 2014 for an estimated $500,000 to help fund the development of the Sia platform. The remaining 8,835 Siafunds are owned by Nebulous, the parent company of Sia. 3.9% of all successful storage contract payouts go to the holders of the Siafunds.

Integrations

 * Nextcloud
 * Minio
 * Duplicati

Community projects

 * Minebox
 * Siaberry
 * SiaDrive
 * SiaCDN

Exchanges that trade Sia
Siacoin trades for Bitcoin and Ether on the following online exchanges:
 * Bittrex
 * Poloniex
 * HitBTC
 * Bisq
 * Abucoins
 * Coinspot (AU)